Petalocephala nigrilinea (Walker)

Petalocephala nigrilinea (Walker) View in CoL

Figs 8C–F View FIGURES 8 , 18 H View FIGURES 18 , 30A–D View FIGURES 30 .

Ledra nigrilinea Walker 1857: 98 View in CoL .

Ledropsis dimidiata Stål 1858: 452 View in CoL : Synonymised by Stål 1866: 104.

Petalocephala nigrilinea (Walker) View in CoL : Distant 1908: 168–169.

Diagnosis. Male. Externally very similar to males of P. latifrons , P. uniformis and P. kirbyi but differing in male genitalia characters. Male pygofer with ventral process. Style apex ventrally curved at right angle distally narrowed with acute apex and with group of short setae as in P. latifrons . Aedeagus tubular, curved, narrowed distally, with angular subapical projection dorsally, without lateral processes, but with one pair of short horn-like processes apically, gonopore apical. It differs from P. latifrons and P. uniformis in not having lateral processes on aedeagal shaft and P. kirbyi differs from it in not having any processes on the aedeagal shaft.

Description. Male. Distant (1908) adequately redescribed the external features of this species. Externally resembling P. latifrons and P. uniformis in coloration and structure. Additional features are as follows. Crown 0.56× as long as interocular distance, o.83× as long as pronotum medially. Pronotal lateral margins slightly diverging posteriorly, distance between posterolateral angles 1.1× longer than that between anterolateral angles and 0.86× as long as mesonotum.

Male genitalia. Pygofer posteriorly conically rounded with ventral process extending to dorsal margin. Subgenital plate longer than pygofer in lateral view. Style in lateral view more or less of uniform width, distal apex curved ventrally at right angle and tapered distally to acute angle, with a patch of short setae as in P. latifrons , but without a subapical tooth.Aedeagus directed posteriorly in proximal region and curved dorsally, abruptly widened in distal 0.33 region with angular projection on dorsolateral surface, then slightly narrowed with one pair of subapical process arising on ventral surface and extending beyond apex of shaft, slightly divergent apically, gonopore apical.

Material examined. SINGAPORE: SYNTYPE 1♂, “Sing.[Singapore]”, “684”, “Wallace”, “Type”, “ Syntype ”, “ nigrilinea Walk. ” “NHMUK 010592232” ( BMNH) .

Remarks. Walker (1857) described this species from an unknown number of male specimens (syntypic) from “ Singapore ”. Distant (1908) adequately redescribed the external features of this species and recorded it from Nilgiri Hills and Sri Lanka. However, it is likely that the latter may be misidentifications of P. uniformis as both the species externally closely resemble each other but have different male genitalia; male pygofer in P. nigrilinea has a ventral process (absent in P. uniformis ) and aedeagal shaft does not have short lateral triangular process (present in P. uniformis ) but has a pair of apical dorsally directed processes (absent in P. uniformis ).